import os
import os.path
import subprocess
import sys
from time import sleep

subprocess.Popen

# print("11.mp4".endswith(".mp4"))
tooladdr = "C:/Users/shikw/Downloads/ffmpeg-20180227-fa0c9d6-win64-static/ffmpeg-20180227-fa0c9d6-win64-static/bin/ffmpeg.exe"
sourcedir = "C:/Users/shikw/Documents"
curlist = os.listdir(sourcedir)
mp4list = list(filter(lambda x: x.endswith(".mp4") , curlist))

for i in range(0,len(mp4list)):
    filefullname = mp4list[i]
    fileinfo = os.path.splitext(mp4list[i])
    cmd = tooladdr+" -i {0} {1}/{2}.mp3 ".format(os.path.join(sourcedir,filefullname),sourcedir, fileinfo[0])
    subprocess.run(cmd , shell=True)

# sleep(50000)